Figure 1. Temperature-gated ion channels known to contribute to thermal sensitivity in somatosensory neurons of vertebrates.

Transient receptor potential channels (TRPV1, TRPA1, TRPM8) sense temperature variations and cause neuronal excitation through sodium and calcium influx. The voltage-gated sodium channel Na_v1.8 contributes to action potential propagation at noxiously cold temperatures. The two-pore ‘leak’ channels (TREK-1, TREK-2, TRAAK) mediate temperature-controlled efflux of potassium, thus contributing to the electric potential on the plasma membrane at rest and counterbalancing the excitatory action of the TRPs during temperature-driven excitation.